<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title>2-3</title>
		<style>
			.c1{
				padding: 20px;
				border:1px solid red;
			}
			.c2{
				padding: 10px;
				margin:10px;
				border:1px dashed green;
				text-align:center ;
			}
		</style>
	</head>
	<body>
		<div class="c1">
		<div class="c2">内容</div>
		</div>
	</body>
</html>
